Summary
PARP inhibitors affect cancer cells by altering their ability to replicate DNA and grow. In theory and in animal models, they work syngergistically with more traditional chemotherapy agents, since PARP inhibition should make chemotherapy (or any drug which damages DNA) more effective. This study was presented at an ASCO plenary session and the reported results are exciting, both for breast cancer and other cancers where these drugs have just begun to be studied.
Analysis
For the last few years, PARP inhibitors have been discussed as having great potential in combination with standard chemotherapy drugs to treat cancer. This paper, a randomized Phase II study treating triple negative breast cancer patients with metastatic disease, showed that patients who received the PARP inhibitor along with standard chemotherapy showed statistically significant improvements in response rate, progression free survival, and overall survival. While this was a small study in only 123 patients, the magnitude of the postive results have prompted the initiation of a Phase III (registration-intent) trial.
This is also important because PARP inhibitors are also being tested in other cancers. For example, Abbott Labs' PARP inhibitor, ABT-888, is currently being tested in trials in melanoma, acute leukemia and myelodysplasia, lymphoma, as well as some other, earlier stage, trials.
